• 한국가스학회지
• /
• 제19권6호
• /
• pp.1-7
• /
• 2015

지구온난화와 화석연료 고갈 문제의 해결을 위하여 대체 연료 개발에 많은 노력을 하고 있다. 암모니아(NH3)는 수소와 마찬가지로 탄소를 포함하고 있지 않으면서 대표적인 수소 캐리어이다. 또한, 상온에서 0.6 MPa 정도의 압력을 가하면 액상을 유지할 수 있어 LPG 충전인프라를 그대로 사용가능한 장점이 있다. 본 연구는 암모니아를 가솔린과 함께 혼소시켰으며, 혼소 비율에 따른 엔진 성능을 비교하였다. 암모니아와 가솔린의 혼소를 위하여 가솔린 인젝터와 암모니아용 인젝터를 각각 사용하였으며, 암모니아는 액상으로 분사시켰다. 암모니아-가솔린 혼소 엔진의 최대 장점은 가솔린 대체량에 비례하여 이산화탄소 배출량을 크 게 감소시킬 수 있다는 것이다. 하지만 암모니아-가솔린 혼소율에 따라 연소가 불안정한 구간이 있었으며, 암모니아 혼소 비율 0.7 이상에서는 연소 불안정성 증가로 인해 토크와 NOx 배출량이 감소하고, THC 배출량이 급증하였다.

• 한국수소및신에너지학회논문집
• /
• 제24권3호
• /
• pp.242-248
• /
• 2013

The purpose of this study is to obtain low-emission and high-efficiency by hydrogen enriched LPG fuel in LPG engine and is to clarify the effects of hydrogen enrichment in LPG fuelled engine on exhaust emission and performance. An experimental study was carried out to obtain fundamental data for performance and emission characteristics of hydrogen enrichment in LPG engine. The research was held by changing the hydrogen ratio to 0, 5, 10, 20% in 1500rpm, bmep 2 and 4bar. The result turned out that the combustion duration was shortened due to fast flame propagation of hydrogen. And the amount of Carbon dioxide and Hydrocarbon decreased. However, the amount of NOX increased, which is thought to be the result of high adiabatic flame temperature of hydrogen. It has been confirmed that this phenomenon has changed by the Hydrogen mixing ratio.

• 한국가스학회지
• /
• 제27권4호
• /
• pp.85-91
• /
• 2023

본 연구에서는 GT24 가스터빈의 1단 연소기인 EV버너를 대상으로 수소연료 혼소에 대한 화염거동, 연소 진동 및 NOx 배출 특성에 대한 실험적 연구를 수행하였다. 수소 혼소율이 증가할수록 NOx 배출 농도가 증가하는 결과를 확인하였다. 이러한 변화는 연료 밀도 변화로 인한 침투깊이 변화, 화염전파속도 증가에 따른 화염위치 변화에 기인한 연료 혼합도 감소와 연소진동으로 인한 시간적 혼합도 섭동 영향이 복합적으로 작용한 결과로 판단되었다. 1.3~3.1bar 범위의 가압 시험을 통해 고압 운전 조건의 NOx 배출 특성을 예측하고 이를 토대로 천연가스용 EV 버너의 수소혼소 한계를 평가하였다.

• 한국수소및신에너지학회논문집
• /
• 제31권4호
• /
• pp.372-379
• /
• 2020

Ammonia-hydrogen dual-fuel engine is a way to reduce greenhouse gas emission because ammonia and hydrogen are carbon-free fuels. In ammonia-hydrogen dual-fuel engine, hydrogen is supplied to improve the combustion characteristic of ammonia. In this study, an ammonia reformer was developed to supply hydrogen for 10 kW class ammonia-hydrogen dual-fuel engine. Thermodynamic characteristic and catalyst were investigated for ammonia reforming. Heat transfer was important for high ammonia conversion of ammonia reformer. 99% of ammonia conversion was obtained when 10 LPM of ammonia and 610℃ of hot gas were supplied to the ammonia reformer.

• 한국자동차공학회논문집
• /
• 제1권2호
• /
• pp.34-41
• /
• 1993

In order to reduce harmful substances such as particulates and nitric oxides emitted from diesel engine, man kinds of methodology like high pressure spray of diesel fuel oil, exhaust gas recirculation, emulsified fuel usage and dual fuelling have been studied. Dual fuelling of a diesel engine with hydrogen which is well-known as the clean fuel and has excellent combustibility is expected to be effective in reducing harmful substances from diesel engine. This experimental study was conducted to investigate the effect of premixed hydrogen with intake air on the performance and particulate emission characteristics using a single cylinder, prechamber type diesel engine. As a result, it was clarified that a hydrogen-premixed diesel engine can be operated in the state of lower particulate emission and slightly aggravated fuel economy, compared with the conventional diesel engine.

• 한국수소및신에너지학회논문집
• /
• 제31권4호
• /
• pp.380-386
• /
• 2020

This paper represents an analysis of the economic impact of firing natural gas/diesel and natural gas/by-product oil mixtures in diesel engine power plants. The objects of analysis is a power plant with electricity generation capacity (300 kW). Using performance data of original diesel engines, the fuel consumption characteristics of the duel fuel engines were simulated. Then, economic assessment was carried out using the performance data and the net present value method. A special focus was given to the evaluation of fuel cost saving when firing natural gas/diesel and natural gas/by-product oil mixtures instead of the pure diesel firing case. Analyses were performed by assuming fuel price changes in the market as well as by using current prices. The analysis results showed that co-firing of natural gas/diesel and natural gas/by-product oil would provide considerable fuel cost saving, leading to meaningful economic benefits.

• 한국수소및신에너지학회논문집
• /
• 제26권4호
• /
• pp.369-376
• /
• 2015

Recently KEPCO, KOGAS and other institutions are jointly conducting an R&D for the development and demonstration of the power generation system based on a natural gas/diesel engine on an island. As a preliminary study, co-combustion in the dual fuel engine, which is expected to produce a few mega-watts of electricity, was modeled and calculated using computational fluid dynamics (CFD). The applied key assumptions are 2-dimensional axisymmetric, transient and static volume chemical reaction. Based on the selected blending ratio, which is the key operating condition, natural gas is substituted instead of diesel fuel (basis of high heating value). Results showed that as the blending ratio increases, the reaction rate of the combustion increases and thus maximum temperature is reached more rapidly. For the optimal performance, various geometric or operational studies will further be conducted.

• 한국수소및신에너지학회논문집
• /
• 제30권5호
• /
• pp.436-447
• /
• 2019

The circulating fluidized bed boiler has an advantage that can burn a variety of fuels from low-grade fuel to coal. In this study, for the design of a circulating fluidized bed boiler using wood pellets, a circulating fluidized bed combustion test device using no external heater was manufactured and used. According to the increase of co-combustion rate with wood pellet, combustion fraction and heat flux by combustor height were measured and pollutant emission characteristics were analyzed. In terms of combustibility, the effect on primary and secondary air ratio were also studied. In addition, as a result of analysis of the effect of corrosive nanoparticles on the combustion of coal with wood pellets, it was confirmed that coal is mostly composed of Ca and S, whereas wood pellets are mostly composed of K, Cl, and Na.

• 한국수소및신에너지학회논문집
• /
• 제24권6호
• /
• pp.524-534
• /
• 2013

Gasoline direct injection(GDI) engine has a high thermal efficiency, but it has a problem to increase carbon emissions such as soot and $CO_x$. In this study, the objective is to analyze numerically a problem for adding the hydrogen during the intake stroke so as to reduce the injected amount of gasoline in GDI engines. For selection of the base model, the cylinder pressure of simulation is matched to experimental data. The numerical analysis are carried out by a CFD model with the hydrogen addition of 2%, 3% and 4% on the volume basis. In the case of 3% hydrogen addition, the injected gasoline amount is only changed to match the maximum pressure of simulation to that of the base model for additional study. It is found that the combustion temperature and pressure increase with the hydrogen addition. And NO emission also increases because of the higher combustion temperature. $CO_x$ emissions, however, are reduced due to the decrease of injected gasoline amount. Also, as the injected gasoline amount is reduced for the same hydrogen addition ratio, the gross indicated work is no significant, But NO and $CO_x$ emissions are considerably decreased. On the order hand, $CO_x$ emissions of two cases are more decreased and their gross indicated works are higher obtained than those of the base model.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2005년도 제17회 워크샵 및 추계학술대회
• /
• pp.414-422
• /
• 2005

유럽에서 RDF기술 확산 동향과 국가별 RDF사용 현황, 각국의 RDF품질표준 및 최근 유럽공통RDF품질표준화 추진현황을 소개하고 RDF사용처별 경제성분석 내용을 소개하였다. 소각로, 시멘트공장 및 석탄화력발전소에서 RDF를 사용할 경우에 열회수량은 시멘트공장이 다소 높게 나타났고 손익평가(cost benefit balance)는 석탄화력발전소가 가장 높게 나타났다. 국내에서 가동 중인 20MW급 순환유동층 석탄화력발전보일러에서 폐플라스틱고형연료(RPF)를 혼합연소하는 기술과 염화수소 및 다이옥신 측정내용을 소개하였다. 전염소량 0.4$\sim$0.6% RPF를 2.5%혼소 시 염화수소는 10ppmv 정도로 분석되었고 다이옥신은 0.003ng-TEQ/$Sm^3$으로 거의 검출이 되지 않았다.